I'm setting a User-ID, when a user visits a given Site. On a certain action, I'm triggering a goal serverside with his User-ID as a parameter (and a token). Effect after the Update from 3.12 to 3.13.2 is that the serverside triggered action is not only stored in another visit (which would be ok), but also fails to recognize the web-visitor with the same User-ID. For reference, the before/after screenshots:

Before (Visitor recognized -> new visit but returning visitor):

After (Visitor is not recognized -> Visit is not returning -> new visit and new visitor):

Serverside call:
https://example.com/piwik.php?token_auth=XXX&cdt=2019-08-07 18:56:10&idgoal=3&revenue=1234&idsite=X&rec=1&r=13454&uid=1234567890

In config, trust_visitor_cookie is disabled.

The reason for that is this change: ea5a14b#diff-6700aaf1ce500fe51e284b9ec6f01b01

The change works in the right direction, but now, a User-ID is only assigned to the same visitor, when also the config_id matches. This doesn't make sense, because the main use case is for example a user who logs into a website with different devices (GDPR aside, but the User-ID is for example the customer ID). This user should be recognized as the same visitor (not necessarily the same visit, but at least the same visitor). @MichaelHeerklotz

Refs #14360